The present invention relates to a position detection system, a game system, and a control method for a position detection system.
A shooting game device that is known in the art enables a plater to use a gun-shaped controller to enjoy simulated shooting.
Game devices that are formed to enable players to use guns to shoot at targets on a screen have become widely popular. In such a game device, a display screen such as a CRT is provided at a predetermined position on a casing, and targets appear on the screen sequentially in accordance with the calculations of a predetermined game program. When a player uses a gun-shaped controller to aim at one of these targets and pulls the trigger, the position at which the gun-shaped controller is aiming is detected by using a position detection circuit and, if that position matches the position of the target, the bullet is determined to have hit that target and a score corresponding to that target is displayed.
It is known in the art to provide a game device that enables shooting at targets displayed on a screen, but without actually firing bullets from such a gun-shaped controller, in which the gun-shaped controller is installed in a holding device that can change the orientation of the gun within fixed angles vertically and horizontally. The orientation of the gun is detected by an encoder or the like that is provided in that holding device. However, since the gun cannot be removed from that holding device for play, a problem arises in that the reality of the game is greatly damaged.
In a known shooting game device that enables play with the gun-shaped controller held freely in the hand, instead of being installed in a holding device, a light-receiving element is provided in the nozzle of the gun-shaped controller. At the same time that the player pulls the trigger of the gun-shaped controller, the screen switches from the game screen to a white screen for position detection, and a raster scan of the white screen starts from a starting point of the top-left corner of the screen. At the same time that the raster scan of the nozzle direction of the gun-shaped controller is performed, the light-receiving element provided in the gun-shaped controller detects light from the raster scan screen, and that raster scan position is detected as the shot position.
The above-described method enables the player to hold the gun freely while playing the game, but since the game screen switches momentarily to a white screen when the player pulls the trigger of the gun-shaped controller, flickering of the game screen occurs every time the trigger of the gun-shaped controller is pulled, which causes a problem in that it leads to tired eyes. Since this change in the screen occurs every time a trigger is pulled, this is particularly irritating when the game is being played by a plurality of players, which leads to a problem in that it kills the players' interest in the game.